1. Technical Field
The present invention relates to a rotor for a rotary electric machine, which is mounted onto vehicles such as passenger vehicles and trucks.
2. Related Art
In a well-known rotary electric machine, a pole core has claw poles on each of which magnets are mounted on both of its circumferential side surfaces to reduce flux leakage. Further, in such a rotary electric machine, a magnet retainer is pressed against each of the side surfaces of each claw pole, using elastic force that acts in the rotation direction of the rotor. Thus, the magnets are each ensured to be held between the claw poles (e.g. see a patent document JP-A-2010-016958). By providing the rotor with such a structure, the magnets are prevented from being displaced in the axial direction when the rotor is rotated.
In the rotor of a rotary electric machine disclosed in the patent document JP-A-2010-016958, each magnet retainer, which is permitted to have an elastic force, is merely partially pressed against the side surface of a claw pole to use the frictional force that acts between the magnet retainer and the claw pole to thereby prevent displacement of the magnet retainer. However, this does not sufficiently prevent displacement caused by a stress, such as vibration. Thus, the rotor as disclosed in the patent document JP-A-2010-016958 suffers from a problem of impairing the reliability of fixing the magnet retainers.
The displacement of the magnet retainers may be alleviated by intensifying the force of partially pressing each magnet retainer against the side surface of a claw pole or against the bobbin of a field winding. However, in this case, each magnet retainer has to inserted and assembled between the claw poles in a state where the magnet retainer is partially pressed such as against the side surface of a claw pole with a strong force, so as not to be displaced. Therefore, the insertion of each magnet retainer requires a large force, disabling easy assemblage of the magnet retainers and thus impairing workability.